Stereochemistry

Question 1

2 Types of Isomers

Answer 1

• Stereoisomers
• Constitutional Isomers

• Stereoisomers: Different arrangement in space
• Constitutional Isomers: Different connectivity (i.e. bonding between atoms differs)

Question 2

2 Types of Stereoisomers

Answer 2

• Enantiomers
• Diastereomers

• Enantiomers: Molecules that are non-superimposable mirror images of one another.
• Diastereomers: Molecules that are non-superimposable, non-mirrored images of one another.

Question 3

Constitutional (Structural) Isomer

Answer 3

Molecules that have the same chemical formula but different connectivity between atoms.

Question 4

Stereoisomers

Answer 4

Molecules that have the same chemical formula and connectivity between atoms, but different arrangments in space.

Question 5

Enantiomers

Answer 5

Molecules that are non-superimposable, mirrored images of one other.

Question 6

Diastereomers

Answer 6

Molecules that are non-superimposable and non-mirrored images of one another.

Question 7

Identical Molecules

Answer 7

Molecules that are superimposable, mirrored images of one another.

Identical molecules are achiral.

Question 8

Stereocenter (Chiral Center)

Answer 8

An sp³-hybridized carbon atom with 4 unique substituents.

Question 9

Polarized Light

Answer 9

Light that vibrates in a single geometric plane.

Question 10

Relative Configuration

Answer 10

cis versus trans

Question 11

Absolute Configuration

Answer 11

(R) versus (S)

Question 12

How does light behave when it passes through a polarizer and an enantiomer?

Answer 12

After the light passes through the polarizer, it begins to vibrate in only one geometric plane (i.e. it becomes polarized). Once the light passes through the enantiomer, it is rotated a certain angle (α) away from the original path of movement.

Question 13

Two isomers that are mirror images of one another and have a plane of symmetry are…?

Answer 13

Identical (Meso)

Question 14

Two isomers that are mirror images of one another and do not have a plane of symmetry are…?

Answer 14

Enantiomers

Question 14

Meso Compound

Answer 14

A compound that possesses an interal plane of symmetry and contains at least two stereocenters that are identical to their mirror images.

Question 15

Do meso compounds rotate polarized light?

Answer 15

No

Question 16

(R,R) and (S,S)

Answer 16

Enantiomers

Question 17

(R,R) and (R,S)

Answer 17

Diastereomers

Question 18

(R,R) and (R,R)

Answer 18

Identical

Question 19

(S,S) and (R,S)

Answer 19

Diastereomers

Question 20

(S,S) and (R,R)

Answer 20

Enantiomers

Question 21

(R,S) and (S,S)

Answer 21

Diasteromers

Question 22

Resolution

Answer 22

The process by which enantiomers can be separated using chemical reactions.

Question 23

Concerted

Answer 23

Occurs in a single step

Question 24

Inversion of Stereochemistry

Answer 24

The (R)-configuration is inverted to the (S)-configuration (and vice versa).

Question 25

Retention of Stereochemistry